# My favourite IIT-JEE Maths question

Although I'm in Class 12,but I couldn't stop myself from taking a glance at this year's JEE Math's questions. I found this question to be very intriguing and so I thought of sharing it with my Brilliant friends.

For $a \in R$ (set of real numbers) , $a \neq -1$, $lim_{n \to \infty}\frac{1^a+2^a+ \ldots +n^a}{(n+1)^{a-1}[(na+1)+(na+2)+\ldots+(na+n)]}= \frac{1}{60}$ Then $a=?$

Note by Shubham Srivastava
6 years, 2 months ago

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The answers are 7 and $\frac{-17}{2}$. The trick here was to first express the limit in form of summation($\Sigma$) and then change summation in definite integration($\int_0^1$).

- 6 years, 1 month ago

8888

- 1 year, 9 months ago

Log questions based on first significant digit

- 1 year, 9 months ago

- 1 year, 9 months ago

7 answer first bind up the expression \this then using sum of limits

- 1 week ago

i just did trail and error....

- 6 years, 2 months ago

Write a comment or ask a question...can you give me the solution

- 3 years, 10 months ago

were there any options given??

- 6 years, 2 months ago

Yes, its a multiple correct answers question.

- 6 years, 2 months ago

a=7

- 6 years, 2 months ago

how?

- 6 years, 2 months ago

You got it?

- 6 years, 2 months ago

I got two answers....a=7 and a= -7/5, but the answer key gives only one. I got a quadratic equation at the end.

Anybody else got the same result?

- 6 years, 1 month ago

a=7 is only accepted

- 3 years, 4 months ago

Answer is 7 or -17/2 ....i guess...

- 1 year, 6 months ago

Determine K so that 2÷3 ,K and 5÷3×k are three consecutive term of an AP

- 1 year, 6 months ago

what's JEE?

- 6 years, 1 month ago

It's the most competitive Engineering Entrance Exam in India.It questions on Physics,Chemistry and Mathematics......

- 6 years, 1 month ago

joint entrance examinations

- 5 years, 8 months ago

how to improve maths skill

- 4 years, 8 months ago

they really gave such easy questions this year?JEE has been diluted.

- 6 years, 2 months ago

Good thing you didn't see the Physics section...

- 6 years, 1 month ago

I took a look,and I see no reason of deviating from my stand.I didn't see anything much innovative,except for a hydrostatics problem in paper 1,and a couple of matching type questions in paper 2.Even those were not really tough,just needed keeping your head cool.Trust me,JEE has seen much better days.

- 6 years, 1 month ago

the chemistry questions were tough, but the maths and the physics questions were found very easy to me.

- 6 years, 1 month ago